Smelly foods may help industry fight obesity, say researchers

Manipulating foods so that they smell stronger could be a way of helping industry fight obesity by encouraging consumers to take smaller bit sizes, suggests new research.

The study – published in the new peer-reviewed journal Flavour – suggests that altering the aroma of food products can help to control portion sizes.

Led by Dr Rene de Wijk of the Top Institute Food and Nutrition, the Netherlands the research team evaluated the effect of food aroma on bite size using a vanilla custard dessert model that was designed to be consumed while different strength cream aromas were delivered to participants’ noses.

The study results suggest that manipulating the smells of food could result in a 5% to 10% decrease in intake per bite.

“Bite size was associated with the aroma presented for that bite and also for subsequent bites,” explained de Wijk, noting that there is an unconscious feedback loop which regulates bite size in correlation to the amount of flavour experienced.

The authors said that combining aroma control with portion control could fool the body into thinking it was full with a smaller amount of food – thus aiding weight loss.

“These results suggest that bite size control during eating is a highly dynamic process affected by the sensations experienced during the current and previous bites,” said the researchers.

In addition to helping industry better understand how aroma can affect portion control, the researchers said the results may also explain why we take smaller bites of unfamiliar or disliked foods.

Study details

The research team assessed the effect of aroma on consumption rates by repeatedly delivering different intensities of aroma into the nose of 10 participants. At the same time a pump fed the participants the custard desert.

"Our human test subjects were able to control how much dessert was fed to them by pushing a button,” said de Wijk.

Over the course of 30 trials the custard was presented randomly either without an aroma, or with aromas presented below or near the detection threshold.

de Wijk and his team found that the intensity of aroma affected the size of the corresponding bite – as well as that of subsequent bites – with higher aroma intensities resulting in significantly smaller ‘bite sizes’.

“Increasing the aroma intensity reduces the bite size,” said the authors, adding that the result fit “into a growing body of literature that suggests that bite size control plays an important role in the self-regulation of food sensations.”